Research Publications (Food Safety)

Unpasteurized milk is used to produce aged artisanal cheeses, which presents a safety concern due to possible contamination with foodborne pathogens, especially Listeria monocytogenes. The objective of this study was to examine the composition of the bacterial community in unpasteurized milk used to prepare Gouda cheese artificially contaminated with L. monocytogenes (~1 log CFU/ml) and assess the community dynamics and their potential interaction with L.

The arctic tundra is undergoing climate-driven changes and there are serious concerns related to the future of arctic biodiversity and altered ecological processes under possible climate change scenarios. Arctic land surface temperatures and precipitation are predicted to increase further, likely causing major transformation in terrestrial ecosystems. As a response to increasing temperatures, shifts in vegetation and soil fungal communities have already been observed.

Prokaryotic tolerance to inorganic arsenic is a widespread trait habitually determined by operons encoding an As (III)-responsive repressor (ArsR), an As (V)-reductase (ArsC), and an As (III)-export pump (ArsB), often accompanied by other complementary genes. Enigmatically, the genomes of many environmental bacteria typically contain two or more copies of this basic genetic device arsRBC.

It has been well documented that cytolethal distending toxin (CDT) from Helicobacter hepaticus (H. hepaticus), Campylobacter jejuni (C. jejuni) and other Gram-negative intestinal pathogens is linked to the inflammatory bowel disease (IBD). However, the mechanisms underlying the progression of H. hepaticus induced colitis remains unclear. In this study, male B6.129P2-IL10tm1Cgn/J mice were infected by H. hepaticus and ΔCdtB H. hepaticus for 6, 12, 18, and 24 weeks. Histopathology, H.

Vibrio parahaemolyticus strains recovered from human diarrheal stools (one in 1975 and two in 2001) and environmental sources (four, between 2008 and 2010) were investigated for the presence of virulence genes (trh, tdh, and vpadF), pandemic markers (orf8, toxRSnew), and with respect to their pathogenic potential in two systemic infection models.

Horizontal gene transfer is an important mechanism which facilitates bacterial populations in overcoming antimicrobial treatment. In this study, a total of 120 Escherichia coli and 62 Salmonella enterica subsp. enterica isolates were isolated from broiler chicken farms in Alberta. Fourteen serovars were identified among Salmonella isolates. Thirty one percent of E.

Commensal bacteria within the gut microbiome contribute to development of host tolerance to infection, however, identifying specific microbes responsible for this response is difficult. Here we describe methods for developing microfluidic organ-on-a-chip models of small and large intestine lined with epithelial cells isolated from duodenal, jejunal, ileal, or colon organoids derived from wild type or transgenic mice.

Within the landscape of globally distributed pathogens, populations differentiate via both adaptive and nonadaptive forces. Individual populations are likely to show unique trends of genetic diversity, host-pathogen interaction, and ecological adaptation. In plant pathogens, allopatric divergence may occur particularly rapidly within simplified agricultural monoculture landscapes.

Wastewater management in the Canadian Arctic is challenging due to climate extremes, small population sizes, and lack of conventional infrastructure for wastewater treatment. Although many northern communities use waste stabilization ponds (WSPs) as their primary form of wastewater treatment, few studies have explored WSP microbial communities and assessed effluent impacts on receiving waters from a microbiological perspective.

Metal contamination from mining or natural weathering is a common feature of surface waters in the American west. Advances in microbial analyses have created the potential for routine sampling of aquatic microbiomes as a tool to assess the quality of stream habitat. We sought to determine if microbiome diversity and membership were affected by metal contamination and identify candidate microbial taxa to be used to indicate metal stress in stream ecosystems.

Microbial resistance to processing treatments poses a food safety concern, as treatment tolerant pathogens can emerge. Occasional foodborne outbreaks caused by pathogenic Escherichia coli have led to human and economic losses. Therefore, this study screened for the extreme heat resistance (XHR) phenotype as well as one known genetic marker, the locus of heat resistance (LHR), in 4,123 E. coli isolates from diverse meat animals at different processing stages.

Biological soil amendments of animal origin (BSAAO) increase nutrient levels in soils to support the production of fruits and vegetables. BSAAOs may introduce or extend the survival of bacterial pathogens which can be transferred to fruits and vegetables to cause foodborne illness.

by Forrest C. Walker, Ebrahim Hassan, Stefan T. Peterson, Rachel Rodgers, Lawrence A. Schriefer, Cassandra E. Thompson, Yuhao Li, Gowri Kalugotla, Carla Blum-Johnston, Dylan Lawrence, Broc T. McCune, Vincent R. Graziano, Larissa Lushniak, Sanghyun Lee, Alexa N. Roth, Stephanie M. Karst, Timothy J. Nice, Jonathan J. Miner, Craig B. Wilen, Megan T. Baldridge

by Iliana Julieta Cortese, María Lorena Castrillo, Andrea Liliana Onetto, Gustavo Ángel Bich, Pedro Darío Zapata, Margarita Ester Laczeski

In this study, we established a rapid and sensitive method for the detection of viable Salmonella Typhimurium, Staphylococcus aureus, and Listeria monocytogenes in milk using biotin-exposure-based immunomagnetic separation (IMS) combined with sodium dodecyl sulfate (SDS), propidium monoazide (PMA), and multiplex real-time PCR (mRT-PCR). We used IMS to lessen the assay time for isolation of target bacteria. We then optimized the coupling conditions and immunomagnetic capture process.

Author(s): Zhenbo Xu, Ziqi Liu, Thanapop Soteyome, Jingjing Hua, Liang Zhang, Yanyan Li, Lei Yuan, Yanrui Ye, Zhao Cai, Liang Yang, Ling Chen, Janette M. Harro, Birthe Veno Kjellerup, Junyan Liu

Author(s): Esther De Rycke, Astrid Foubert, Peter Dubruel, Oleg I. Bol'hakov, Sarah De Saeger, Natalia Beloglazova

Author(s): Zhe-Yu Yang, Wei-Liang Chen

Author(s): Amin N. Olaimat, Mahmoud Abu Ghoush, Murad Al-Holy, Haneen Abu Hilal, Anas A. Al-Nabulsi, Tareq M. Osaili, Mutamed Ayyash, Richard A. Holley

Author(s): Qing Chen, Yaxin Liu, Ziyi Zhang, Ke Li, Bin Liu, Tianli Yue

Author(s): Bowen Chen, Jiaming Huang, Yang Liu, Haiquan Liu, Yong Zhao, Jing Jing Wang

Author(s): Jade Derrick, Philippa Hollinghurst, Sarah O'Brien, Nicola Elviss, David J. Allen, Miren Iturriza-Gómara

Author(s): Wenxuan Dong, Gang Liu, Kanglei Zhang, Yun Tan, Hui Zou, Yan Yuan, Jianhong Gu, Ruilong Song, Jiaqiao Zhu, Zongping Liu

Author(s): Fasih Ullah Haider, Jeffrey A. Coulter, Sardar Alam Cheema, Muhammad Farooq, Jun Wu, Renzhi Zhang, Guo Shuaijie, Cai Liqun

Author(s): Tingting Fan, Yanli Xie, Weibin Ma